PWCT is General purpose visual programming language wherein the programmer need not write code but can visually specify every functional aspect of the program similar to flowcharts and algorithms.
PWCT is free-open source and uses Interaction by presenting a GUI between a Human language and a Programming language; so doing anything requires knowing Procedure instead of being Declarative.

The next online movies provide practical introduction to HarbourPWCT where HarbourPWCT let us Develop applications using Programming Without Coding Technology - then we get Harbour/xHarbour source Code.